U.S. patent application number 10/878791 was filed with the patent office on 2005-12-29 for dynamic fluid delivery system with compensation.
Invention is credited to Nichols, Steven C..
Application Number | 20050284622 10/878791 |
Document ID | / |
Family ID | 35504355 |
Filed Date | 2005-12-29 |
United States Patent
Application |
20050284622 |
Kind Code |
A1 |
Nichols, Steven C. |
December 29, 2005 |
Dynamic fluid delivery system with compensation
Abstract
Flow is managed within a fluid delivery system such as an HVAC
system. In one illustrative embodiment, a method is provided for
controlling the airflow and thus the heat delivery rate to a room
serviced by an HVAC system. The HVAC system includes a duct system
that is in fluid communication with a room through a damper or the
like. Other embodiments are also disclosed.
Inventors: |
Nichols, Steven C.; (Maple
Grove, MN) |
Correspondence
Address: |
HONEYWELL INTERNATIONAL INC.
101 COLUMBIA ROAD
P O BOX 2245
MORRISTOWN
NJ
07962-2245
US
|
Family ID: |
35504355 |
Appl. No.: |
10/878791 |
Filed: |
June 28, 2004 |
Current U.S.
Class: |
165/205 |
Current CPC
Class: |
F24F 11/76 20180101;
F24F 11/30 20180101; G05D 23/1934 20130101; F24F 11/62
20180101 |
Class at
Publication: |
165/205 |
International
Class: |
F24F 003/00 |
Claims
What is claimed is:
1. A method of controlling an HVAC system having a plurality of
zones, wherein each zone includes one or more zone dampers, the
method comprising the steps of: determining an open/closed state of
at least some of the zone dampers; and adjusting an open time for
at least selected zone dampers based on the state of the at least
some of the zone dampers.
2. The method of claim 1, wherein the adjusting step adjusts the
open time based on how many of the zone dampers are in an open
state relative to how many of the zone dampers are in a closed
state.
3. A method of regulating an HVAC system that includes a duct
system having a damper, the method comprising the steps of: opening
the damper; and leaving the damper open for an open time period,
wherein the open time period is dependent on a heat delivery rate
through the damper.
4. The method of claim 3, wherein the HVAC system includes a
multiple speed blower, and the heat delivery rate through the
damper is dependent upon a speed of the blower.
5. The method of claim 3, wherein the HVAC system includes at least
one additional damper, and the heat delivery rate through the
damper depends upon whether the at least one additional damper is
open or closed.
6. A method of controlling thermal energy delivery to a zone within
an HVAC system having two or more zones, wherein airflow to at
least selected zones is controlled by one or more zone dampers, and
wherein the thermal energy provided by the HVAC system to each of
the zones is dependent on the open/closed state of at least some of
the other zone dampers, the method comprising the steps of: opening
a zone damper; leaving the zone damper open for an open time
period, wherein the open time period is dependent on the state of
one or more other zone dampers.
7. The method of claim 6, wherein the zone damper includes an
initial open time period, and the initial open time period is
reduced by an amount that is dependent on the state of one or more
other zone dampers, resulting in the open time period.
8. The method of claim 7, wherein the zone damper corresponds to a
particular zone, and the particular zone has a thermal demand,
wherein the initial open time period is dependent on the thermal
demand of the particular zone.
9. The method of claim 6, wherein the zone damper is left open
until a counter counts to a predetermined value
10. The method of claim 9, wherein the predetermined value is set
such that the counter counts to the predetermined value in the open
time period.
11. The method of claim 9, wherein the counter counts by a counter
increment value, wherein the counter increment value is set such
that the counter counts to the predetermined value in the open time
period.
12. The method of claim 9, wherein the counter counts by a counter
increment value once during each counter period, wherein the
counter period is set such that the counter counts to the
predetermined value in the open time period.
13. The method of claim 9, wherein the counter is incremented.
14. The method of claim 9, wherein the counter is decremented.
15. A method of managing an HVAC system having two or more zones,
wherein each zone includes at least one zone damper, the method
comprising the steps of: determining a measure of thermal demand
for a zone; determining a measure of available thermal energy for
the zone; and operating a damper within the zone in accordance with
the thermal demand and the available thermal energy.
16. The method of claim 15, wherein the measure of the available
thermal energy of the zone is dependant at least in part on the
number of open zone dampers within the HVAC system and the total
number of zone dampers within the HVAC system.
17. The method of claim 15, further comprising the step of
periodically recalculating the measure of thermal demand in the
zone.
18. The method of claim 15, further comprising the step of
periodically recalculating the measure of available thermal energy
for the zone.
19. A method of dynamically controlling an HVAC system having two
or more zones, each zone having one or more zone dampers, the
method comprising the steps of: selecting a zone from the two or
more zones; determining a measure of thermal demand for the
selected zone; determining a measure of available thermal energy
for the selected zone; and calculating an operational profile for
the selected zone based on the measure of thermal demand and the
measure of available thermal energy; wherein the operational
profile provides open and close times for the one or more zone
dampers for the selected zone.
20. The method of claim 19, further comprising a subsequent step of
operating the selected zone in accordance with the corresponding
operational profile.
21. The method of claim 19, wherein the calculating step comprises
adjusting the open and close times to accommodate the available
thermal energy for the selected zone.
22. The method of claim 19, further comprising the step of
periodically recalculating the measure of thermal demand for the
selected zone.
23. The method of claim 19, further comprising the step of
periodically recalculating the operational profile for the selected
zone.
24. The method of claim 19, wherein the HVAC system includes a
forced air heating system.
25. The method of claim 19, wherein the HVAC system includes a
forced air cooling system.
26. A method of controlling thermal energy delivery in a system
comprising a plurality of zones, the method comprising the steps
of: selecting a zone based on its thermal demand; calculating a
zone open time based on the thermal demand of the zone; determining
a status of each of the zones within the multi-zone system;
calculating a compensation value based on the status of each of the
zones; and adjusting the zone open time as a function of the
compensation value.
27. The method of claim 26, wherein the selecting step comprises
selecting a zone having a greatest thermal demand.
28. The method of claim 26, wherein the calculating step includes
calculating the compensation value based, at least in part, on a
total number of zones versus a total number of open zones.
29. The method of claim 26, wherein the adjusting step adjusts the
zone open time based, at least in part, on the zone open time and
the compensation value.
30. The method of claim 29, wherein the adjusting step adjusts the
zone open time based, at least in part, on the zone open time
divided by the compensation value.
31. A method for controlling the opening and closing of a damper in
an HVAC system, wherein the damper is coupled to a duct that
delivers air to the damper, and wherein the duct is fluidly
connected to one or more other dampers and/or valves that can
assume open and closed positions, the method comprising the steps
of: opening the damper for a length of time; closing the damper
after the length of time; and wherein the length of time is
dependent on the position of at least one of the other dampers
and/or valves that is fluidly connected to the duct.
32. A method of controlling an HVAC system that includes a duct
system, wherein the duct system has a pressure when the HVAC system
is operating, the method comprising the steps of: activating the
HVAC system to supply condition air into the duct system; and
continuing to operate the HVAC system in a continuous manner for an
operating time period, wherein the operating time period is
dependent, at least in part, on the pressure in the duct system.
Description
TECHNICAL FIELD
[0001] The present invention generally relates to fluid delivery
systems, and more particularly, to fluid delivery systems adapted
for thermal energy compensation.
BACKGROUND
[0002] Fluid delivery systems are commonly used today in a wide
variety of applications. Air delivery systems such as forced air
systems are commonly used to deliver conditioned air to one or more
locations within a house or building. Water delivery systems such
as sprinkler systems are commonly used for delivering water to
sprinkler heads in, for example, a buried sprinkler system or in a
fire prevention sprinkler system. Water circulation systems are
commonly used to heat and/or cool both residential and commercial
buildings. These are just a few examples of fluid delivery
systems.
[0003] Fluid delivery systems often include a network of pipes or
ducts. In many cases, one or more valves or dampers, such as zone
valves or dampers, are used to control the fluid flow through all
or part of the pipes or ducts of the distribution network. In some
cases, the network of pipes or ducts is broken up into zones, where
some or all of the zones can be independently activated by one or
more corresponding zone valves or dampers.
[0004] In a fluid delivery system such as described herein, the
amount of fluid available to a particular zone can vary depending
on how many other zone valves or dampers are open or closed. In a
water delivery system such as an underground sprinkler system, the
amount of water pressure available to a specific sprinkler head
will depend on a gross water pressure available to the system
itself as well as the number of open sprinkler heads at any given
time. In a forced air delivery system such as a forced air heating
or cooling system, the amount of conditioned air available to a
specific zone will often depend on the gross thermal capacity of
the heating or cooling system, as well as the number of open zones
at any given time.
[0005] In many forced air heating and cooling systems, each zone
will have a damper that controls air flow to the particular zone.
The zone damper can open to permit conditioned air to flow into the
zone from a source of conditioned air. The amount of heating or
cooling delivered to the zone is often a function of the thermal
capacity of the conditioned air and the relative amount of time
that the zone damper is open.
[0006] As noted, the actual amount of conditioned air (and thus the
amount of heating or cooling delivered) can vary depending on, for
example, the number of open zones or dampers relative to the total
number of zones or dampers in the system. For example, as zone
dampers close over time, more heating and/or cooling may be
delivered through the remaining open dampers, sometimes resulting
in significant variations in the amount of heating and/or cooling
that is delivered to each remaining open zone. This variation in
the amount of heating and/or cooling that is delivered to a zone
can significantly degrade a controllers ability to maintain
adequate temperature control within a zoned system. Thus, a need
remains for methods and system for controlling forced air and/or
other systems that can account for the status of other zones within
a multi-zone system.
SUMMARY
[0007] The present invention generally relates to fluid delivery
systems, and in some cases, zoned fluid delivery systems such as
zoned HVAC systems.
[0008] In one illustrative embodiment, a method is provided for
controlling an HVAC system that has a number of zones that each has
one or more zone dampers. An open/closed state for at least some of
the zone dampers can be determined, and an open time for at least
selected zone dampers can be adjusted based on the state of at
least some of the zone dampers. In some instances, the open time
can be adjusted based on how many of the zone dampers are in an
open state relative to how many of the zone dampers are in a closed
state.
[0009] In some embodiments, the zone damper includes an initial
open time that can be reduced by an amount that is dependent on the
status of one or more other zone dampers. In some cases, the
initial open time period can depend upon a thermal demand of a
particular zone that is associated with the zone damper.
[0010] In another illustrative embodiment, a method is provided for
regulating an HVAC system that includes a duct system having a
damper. The damper can be opened and the damper can be left open
for an open period of time that can be dependent upon a heat
delivery rate through the damper. In some cases, the HVAC system
can include a multiple speed blower and the heat delivery rate
through the damper can be dependent upon the speed at which the
blower is operating. In other cases, the HVAC system can include at
least one additional damper, and the heat delivery rate through the
damper can depend upon whether the additional damper is open or
closed.
[0011] In yet another illustrative embodiment, a method is provided
for managing an HVAC system that has two or more zones each
including at least one zone damper. A measure of thermal demand and
a measure of available thermal energy can be determined for a zone.
A damper can be operated in accordance with the measure of thermal
demand and the measure of available thermal energy. In some
instances, the measure of the available thermal energy of the zone
is dependant at least in part on the number of open zone dampers
within the HVAC system and the total number of zone dampers within
the HVAC system.
[0012] In particular embodiments, the method can include an
additional step of periodically recalculating the measure of
thermal demand in the zone. In some embodiments, the method can
include an additional step of periodically recalculating the
measure of available thermal energy for the zone.
[0013] In yet another illustrative embodiment, a method is provided
for dynamically controlling an HVAC system that has two or more
zones, with each zone having one or more zone dampers. A zone can
be selected from the two or more zones. A measure of thermal demand
and a measure of available thermal energy can be determined for the
selected zone. An operational profile based on the measure of
thermal demand and the measure of available thermal energy can be
calculated. In some instances, the operational profile can provide
open and close times for the zone dampers within the selected zone.
The method can include a subsequent step of operating the selected
zone in accordance with the operational profile.
[0014] In some instances, the step of calculating the operational
profile can include adjusting the open and close times to account
for the amount of thermal energy available to the selected zone. In
some cases, the thermal demand for the selected zone can be
periodically recalculated and consequently the operational profile
can be accordingly adjusted as necessary.
[0015] In yet another illustrative embodiment, a method of
controlling thermal energy delivery in a system having a number of
zones is provided. A zone can be selected based on its thermal
demand, and a zone open time can be calculated based on the thermal
demand of the zone. A status of each of the zones can be determined
and a compensation value can be calculated based on the status of
each of the zones. The zone open time can be adjusted as a function
of the compensation value. In some instances, the zone selected is
the zone having the greatest thermal demand.
[0016] In some cases, the compensation value can be calculated
based at least in part on a total number of zones relative to a
total number of open zones. The compensation value can be used to
adjust the zone open time. In some instances, the zone open time is
adjusted by dividing the zone open time by the compensation
value.
[0017] In yet another illustrative embodiment, a method for
controlling the opening and closing of a damper in an HVAC system
is provided. The damper can be coupled to a duct that delivers air
to the damper and that is fluidly connected to one or more other
dampers or valves that can assume open and closed positions. The
damper can be opened for a length of time and can subsequently be
closed after the length of time. In some instances, the length of
time can be dependent on the position of at least one of the other
dampers or valves that are fluidly connected to the duct.
[0018] In yet another illustrative embodiment, a method of
controlling an HVAC system is provided. The HVAC system can include
a duct system that has a pressure when the HVAC system is
operating. The HVAC system can be activated to supply conditioned
air into the duct system and can continue to operate in a
continuous manner for an operating time period. In some instances,
the operating time period can be dependent, at least in part, on
the pressure in the duct system.
[0019] The above summary of the present invention is not intended
to describe each disclosed embodiment or every implementation of
the present invention. The Figures, Detailed Description and
Examples which follow more particularly exemplify these
embodiments.
BRIEF DESCRIPTION OF THE FIGURES
[0020] The invention may be more completely understood in
consideration of the following detailed description of various
embodiments of the invention in connection with the accompanying
drawings, in which:
[0021] FIG. 1 is a block diagram of a controller in accordance with
an illustrative embodiment of the present invention;
[0022] FIG. 2 is a schematic illustration of an HVAC system in
accordance with an illustrative embodiment of the present
invention;
[0023] FIG. 3 is a schematic illustration of an HVAC system in
accordance with an illustrative embodiment of the present
invention;
[0024] FIG. 4 is a schematic illustration of an HVAC system in
accordance with an illustrative embodiment of the present
invention;
[0025] FIG. 5 is a flow diagram showing an illustrative method that
may be implemented by the controller of FIG. 1;
[0026] FIG. 6 is a flow diagram showing another illustrative method
that may be implemented by the controller of FIG. 1;
[0027] FIG. 7 is a flow diagram showing yet another illustrative
method that may be implemented by the controller of FIG. 1;
[0028] FIG. 8 is a flow diagram showing yet another illustrative
method that may be implemented by the controller of FIG. 1;
[0029] FIG. 9 is a flow diagram showing yet another illustrative
method that may be implemented by the controller of FIG. 1;
[0030] FIG. 10 is a flow diagram showing yet another illustrative
method that may be implemented by the controller of FIG. 1;
[0031] FIG. 11 is a flow diagram showing yet another illustrative
method that may be implemented by the controller of FIG. 1;
[0032] FIG. 12 is a flow diagram showing yet another illustrative
method that may be implemented by the controller of FIG. 1;
[0033] FIG. 13 is a flow diagram showing yet another illustrative
method that may be implemented by the controller of FIG. 1;
[0034] FIG. 14 is a flow diagram showing yet another illustrative
method that may be implemented by the controller of FIG. 1;
[0035] FIG. 15 is a flow diagram showing yet another illustrative
method that may be implemented by the controller of FIG. 1;
[0036] FIG. 16 is a flow diagram showing yet another illustrative
method that may be implemented by the controller of FIG. 1;
[0037] FIG. 17 is a flow diagram showing yet another illustrative
method that may be implemented by the controller of FIG. 1; and
[0038] FIG. 18 is a flow diagram showing yet another illustrative
method that may be implemented by the controller of FIG. 1.
[0039] While the invention is amenable to various modifications and
alternative forms, specifics thereof have been shown by way of
example in the drawings and will be described in detail. It should
be understood, however, that the intention is not to limit the
invention to the particular embodiments described. On the contrary,
the intention is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the invention.
For example, while HVAC systems are primarily featured as
illustrative embodiments herein, it is contemplated that the
present invention may be applied to any type of fluid delivery
system, as desired.
DETAILED DESCRIPTION
[0040] The following description should be read with reference to
the drawings, in which like elements in different drawings are
numbered in like fashion. The drawings, which are not necessarily
to scale, depict selected embodiments and are not intended to limit
the scope of the invention. Although examples of construction,
dimensions, and materials are illustrated for the various elements,
those skilled in the art will recognize that many of the examples
provided have suitable alternatives that may be utilized.
[0041] The present invention generally pertains to pressurized
fluid distribution systems that provide fluid through a pipe or
duct network to one or more distinct distribution points. In one
illustrative embodiment, the present invention may include an HVAC
system that provides conditioned air through ductwork to two or
more distinct zones. Each zone can include a damper or similar
structure that can move between a closed position in which the
damper permits little or no air to pass into the zone and an open
position in which the damper provides little or no resistance to
conditioned air passing into the zone.
[0042] In some cases, the HVAC system provides a relatively
constant volume of conditioned air, typically dictated by the HVAC
fan size and fan speed. In some instances, however, the HVAC system
can include a multiple speed fan. Consequently, the fan can operate
at several different speeds in accordance with desired conditioned
air volume. In many instances, while the fan speed itself can vary,
the thermal output of the HVAC system is essentially constant. In
many cases, both furnaces and air conditioning systems are
configured to run at a single thermal output. For example, a
typical forced air furnace may provide a constant 90,000 BTUs of
heat while a typical air conditioning system may provide 2.5 tons
of cooling (one ton of cooling equates to 12,000 BTU of removed
heat).
[0043] In some instances, however, the thermal output of the HVAC
system can vary. In some cases, several individual burners or
furnaces can be combined in a single system. In circumstances
requiring relatively lower amounts of heat, perhaps only one burner
or furnace will operate. However, if relatively larger amounts of
heat are required, a second or even perhaps a third burner or
furnace will operate. In other instances, a furnace such as a
forced air furnace can be configured to adjust the fuel flow to its
burner or burners and can in this way adjust its thermal
output.
[0044] Referring now to FIG. 1, which shows a controller 10 in
accordance with an illustrative embodiment of the present
invention. Controller 10 includes a control module 12 that is
configured to monitor and control a system such as an HVAC system
14. Controller 10 also includes a user interface 16 that is
configured to provide communication between control module 12 and a
user. User interface 16 can be used to communicate status of HVAC
system 14 to the user, and/or accept input from the user.
[0045] User interface 16 can take a wide variety of different
forms. User interface 16 can include one or more of an
alpha-numeric display, a graphical display, and/or a key pad having
one or more keys or buttons. In some embodiments, user interface 16
can include a touch screen. In other embodiments, user interface 16
can include a display screen and one or more buttons. In some
embodiments, a thermostat can function as user interface 16. In
systems having more than one zone, a separate thermostat can be
positioned within each zone and can together function as user
interface 16.
[0046] Control module 12 also communicates with zone 18, zone 20
and zone 22. As illustrated, control module 12 communicates with at
least three zones 18, 20 and 22, although the invention
contemplates systems having, in some cases, one, two, as well more
than three zones. Zone 18, 20 and 22 are labeled as "zone n-1",
"zone n" and "zone n+1", respectively, with "n" being an integer
number. For example, in a hypothetical system having 10 zones, "n"
can be an integer that ranges from 2 to 9. To illustrate, if "n" is
set equal to 5, zone 18 represents "zone 4", zone 20 represents
"zone 5", and zone 22 represents "zone 6".
[0047] As will be discussed in greater detail hereinafter, each of
zone 18, zone 20 and zone 22 can include one or more dampers that
can be reversibly moved between an open position and a closed
position. In some cases, control module 12 can provide or receive
signals from each of zone 18, zone 20 and zone 22 indicating the
relative position of each damper or dampers within each of zone 18,
zone 20 and zone 22. In particular, and in one illustrative
embodiment, each zone 18, 20 and 22 can include a single damper
controlling fluid flow into each zone 18, 20 and 22.
[0048] With reference to FIGS. 2-4, and in the illustrative
embodiment, an HVAC system can include any number of distinct zones
that provide individualized control over the flow of conditioned
air into each distinct zone. FIG. 2 in particular illustrates a
system 32 including controller 10 and HVAC system 14. System 32
includes a first zone 34 and a second zone 36. Controller 10 is in
communication with first zone 34 and second zone 34, as well as
with HVAC system 14. FIG. 3 illustrates a system 38 in which
controller 10 is in communication with a first zone 40, a second
zone 42 and a third zone 44, as well as HVAC system 14. FIG. 4
illustrates a system 46 in which the three zones shown are
generically referenced as zone 18, zone 20 and zone 22 as described
above.
[0049] With reference to FIG. 1, control module 12 may include a
memory block 24 that can store one or more parameter values. Memory
block 24 can also store a program that controls the operation of
the controller 10, and thus the operations of the HVAC system 14.
The program stored within memory block 24 can include instructions
for operating HVAC system 14, including turning HVAC system 14 on
or off based on a timed schedule. For example, the program can
include time and temperature set points.
[0050] As noted above, control module 12 communicates with a user
through user interface 16. Thus, control module 12 may include a
USER I/O block 26 that can include circuitry or software that sends
information to user interface 16 and that receives and if necessary
translates or modifies signals from user interface 16.
[0051] HVAC system 14 can include any desired HVAC equipment. In
some embodiments, HVAC system 14 can include a heating plant such
as a furnace or a heat pump. HVAC system 14 can also include an air
conditioner or a combination of heating and cooling equipment.
[0052] In the illustrative embodiment control module 12 also
includes a ZONE I/O block 28 that can include software or circuitry
that sends signals to one or more of zone 18, zone 20 and zone 22.
Such signals can include instructing a damper within one of zone
18, zone 20 and zone 22 to move from an open position to a closed
position, or perhaps from a closed position to an open position, or
in some cases, an intermediate position. ZONE I/O block 28 may also
receive signals from one or more of zone 18, zone 20 and zone 22.
Such signals can inform control module 12 of the relative position
of one or more dampers within one or more of zone 18, zone 20 and
zone 22. Such signals can also include temperature signals from
temperature sensors within one or more of zone 18, zone 20 and zone
22.
[0053] Control module 12 may also include an HVAC I/O block 30 that
can include software or circuitry that sends and receives signals
between control module 12 and HVAC system 14. Control module 12 can
send instructional signals such as on/off commands and equipment
selection commands to HVAC system 14. If HVAC system 14 includes a
variable speed fan and/or is configured to provide varying thermal
outputs, HVAC I/O block 30 can provide HVAC system 14 with the
appropriate instructions to vary the fan speed and/or the burner
output. HVAC system 14 can in turn send informational signals such
as confirming commands to control module 12. Illustrative
interactions between MEMORY block 24, USER I/O block 26, ZONE I/O
block 28 and HVAC I/O block 30 are further illustrated below with
respect to, for example, FIGS. 5 through 18.
[0054] FIG. 5 is a flow diagram showing an illustrative method that
can be implemented by controller 10. At block 48, controller 10
determines the open or closed state of at least some dampers. In
some embodiments, HVAC system 14 can provide conditioned air, i.e.
heated air or cooled air, to a system of ductwork that provides the
conditioned air to one or more rooms within a house or other
structure. If for example the ductwork provides conditioned air to
five rooms, the ductwork system may include five dampers that are
adapted to regulate airflow into each of the five rooms. Thus, in
the example discussed, controller 10 can determine the open or
closed status of one, two, three, four or five of the five dampers
present in the ductwork system.
[0055] At block 50, controller 10 adjusts an open time of one or
more selected dampers based at least in part on the status of at
least some of the other dampers within the ductwork system.
Controller 10 can adjust the open time of the one or more selected
dampers in accordance with algorithms that will be discussed in
greater detail hereinafter.
[0056] FIG. 6 is a flow diagram showing an illustrative method that
can be implemented by controller 10. At block 52, controller 10
instructs a damper to open. In some instances, ZONE I/O block 28
(FIG. 1) signals the appropriate zone damper to open. Control
passes to block 54, where controller 10 leaves the zone damper open
for an open time period. Calculation of the open time period is
done by controller 10 using the algorithms discussed in greater
detail hereinafter.
[0057] FIG. 7 is a flow diagram showing an illustrative method that
can be implemented by controller 10. At block 52, controller 10
instructs a damper to open. In some instances, ZONE I/O block 28
(FIG. 1) signals the appropriate zone damper to open. At block 56,
controller 10 determines an open time period based at least in part
on a heat delivery rate to a particular zone. The heat delivery
rate can be a function both of the thermal capacity of HVAC system
14 as well as the relative airflow through the ductwork. As noted
above, relative airflow can vary both as a function of fan speed
and in relation to the number of open versus closed zone dampers
within the ductwork. Control passes to block 58, where controller
10 leaves the zone damper open for an open time period.
[0058] FIG. 8 is a flow diagram showing an illustrative method that
can be implemented by controller 10. At block 52, controller 10
instructs a damper to open. In some instances, ZONE I/O block 28
(FIG. 1) signals the appropriate zone damper to open. Control
passes to block 60, where controller 10 determines an open time
period for the appropriate zone damper. The open time period can be
calculated at least in part as a function of the status of one or
more other zone dampers. While the flow diagram shows calculation
of the open time period as subsequent to opening the zone damper,
the invention contemplates calculating the open time period prior
to opening the zone damper or simultaneously with opening the zone
damper, as desired. Control passes to block 58, where controller 10
leaves the zone damper open for an open time period.
[0059] FIG. 9 is a flow diagram showing an illustrative method that
can be implemented by controller 10. At block 62, controller 10
determines the thermal demand of a zone. For illustrative purposes,
and referring to FIG. 4, say that controller 10 determines the
thermal demand of zone 20. In this example, thermal demand can be
defined as an amount of thermal energy that can be added to or
removed from zone 20 in order to reach a desired temperature. The
thermal demand of zone 20 can be positive, indicating a need to add
additional heat to zone 20. The thermal demand of zone 20 can also
be negative, indicating a need to remove heat from zone 20. This
can be accomplished by actively cooling zone 20, or alternatively,
by simply not providing additional heat to zone 20 and allowing
zone 20 to cool through radiant cooling, for example.
[0060] In some respects, thermal demand can also be defined in
terms of a temperature difference between an actual temperature
within zone 20 and a desired temperature set point for zone 20. In
some embodiments, controller 10 can be in communication through
user interface 16 (FIG. 1) with a thermostat. The thermostat can
provide controller 10 with information regarding desired
temperature set points as well as an actual current temperature
within a particular zone.
[0061] Once the thermal demand of zone 20 has been determined,
control passes to block 64. At block 64, controller 10 determines
an available airflow for zone 20. MEMORY block 24 (FIG. 1) can
include or be programmed with information regarding the airflow
available from HVAC system 14. In some embodiments, airflow can be
defined in terms of airflow velocity or volume, and can represent
the airflow velocity or volume that can be reproduced by HVAC
system 14. In some embodiments, HVAC system 14 has a constant
thermal capacity and a single fan speed and thus airflow through
the ductwork is a function of how many zone dampers are open versus
how many zone dampers are closed.
[0062] In some embodiments, especially in larger buildings with a
large number of zones and perhaps several main feeder trunk duct
lines, the data regarding the airflow capacity of HVAC system 14
can include data regarding the maximum airflow available at a given
trunk duct line. In some embodiments, the trunk duct line can be
considered as the source of conditioned air.
[0063] The amount of air available to a particular zone can vary
depending on the status of other zones operatively connected to
HVAC system 14. For example, when all of the zone dampers are open,
the pressure in the ductwork may be lower than when only one of the
zone dampers is open. As a result, more air flow may result in an
open zone when all or some of the other zones are closed.
[0064] Controller 10 can inquire as to the status of each zone in
the system. In the illustrative example and with respect to FIG. 4,
controller 10 can send (or receive) a signal to each of zone 18 and
22 via ZONE I/O block 28 to determine the status of each of zone 18
and 22. It should be noted that if n=2, the system includes a total
of three zones. However, in many embodiments, n is greater than 2.
In such cases, controller 10 can query the status of all of the
other zones, if desired.
[0065] In some embodiments, controller 10 can determine the airflow
available to zone 20 as a function of the airflow capacity of HVAC
system 14 (FIG. 4), a total number of zones in the system, and a
total number of closed zones and/or a total number of open zones in
the system. As the number of closed zones increases relative to a
total number of zones in HVAC system 14, the available airflow to
one or more zones that remain open will tend to increase, and the
pressure in the ductwork will also increase. As will be discussed
in greater detail hereinafter, controller 10 can be configured to
account for this possible variation in airflow available to a
particular zone.
[0066] In the illustrative embodiment, and once available airflow
has been calculated, control passes to block 66, where controller
10 can calculate an operational profile for a given zone. In the
illustrated example, controller 10 can calculate an operational
profile for zone 20. In some embodiments, as will be discussed in
greater detail hereinafter, the operational profile can include one
or more times for either opening or closing the damper that
regulates airflow into a given zone, such as illustrative zone
20.
[0067] In some embodiments, MEMORY block 24 (FIG. 1) can include
data regarding the thermal capacity of HVAC system 14. This data
can provide controller 10 with information concerning the maximum
heating capacity, say in British Thermal Units (Btu), that HVAC
system 14 can produce, or perhaps the maximum cooling capacity, say
in Tons cooling. If HVAC system 14 is capable of adjusting its
thermal output as discussed above, the data can include this
information as well. The data can also provide controller 10 with
data concerning the total number of zones in the system, and in
some cases, the heat load presented by each zone.
[0068] In some embodiments, especially in larger buildings with a
large number of zones and perhaps several main feeder trunk duct
lines, the data regarding the thermal capacity of HVAC system 14
can include data regarding the maximum heating or cooling capacity
available at a given trunk duct line. In some embodiments, the
trunk duct line can be considered as the source of conditioned
air.
[0069] As noted, controller 10 can be configured to determine an
operational profile for a given zone. The operational profile can
include times for either opening or closing a damper that regulates
airflow into a given zone (zone 20 in the illustrative example). In
some embodiments, controller 10 can determine, based on the thermal
demand of the zone, the thermal capacity of HVAC system 14, and the
airflow available to the given zone, appropriate times for opening
and closing the damper to achieve a desired temperature set point
within the given zone.
[0070] FIG. 10 is a flow diagram showing another illustrative
method that can be implemented by controller 10. At block 62,
controller 10 (FIG. 1) determines the thermal demand of a
particular zone. This can be accomplished as discussed above with
respect to FIG. 9, for example. Control passes to block 64, at
which time controller 10 determines the thermal energy available
for the particular zone.
[0071] In some instances, the thermal energy available for the
particular zone can be a fraction of the total thermal capacity of
HVAC system 14, where the fraction can be a function of the number
of open zone dampers. As the number of open zone dampers decreases,
a relatively greater volume of conditioned air will be available to
each open zone damper.
[0072] In some cases, controller 10 can instruct HVAC system 14 to
operate at a lower fan or blower speed when a relatively large
number of zone dampers are closed. If HVAC system 14 continues to
operate at a constant thermal capacity, the amount of air available
to an open zone may remain relatively constant, but the amount of
thermal energy present within the air will increase (if for example
HVAC system 14 is providing heat). In other instances, HVAC system
14 can operate at a variable thermal capacity as discussed above.
The amount of thermal energy available to a particular zone may be
a function of each of these factors.
[0073] At block 66, controller 10 calculates an operational profile
for the zone. Controller 10 can utilize any suitable algorithm to
calculate the operational profile, although particular algorithms
are discussed hereinafter.
[0074] Control passes to block 68, with controller 10 (FIG. 1)
controlling or operating the given zone in accordance with the
operational profile. In some embodiments, controller 10 can issue
commands through ZONE I/O block 28 (FIG. 1) to either open or close
a damper in a given zone 18, 20 or 22. In the example shown,
controller 10 may manage an operational profile calculated for zone
20. Controller 10 can also issue commands if necessary to HVAC
system 14 through HVAC I/O block 30 (FIG. 1). Suitable commands
include instructing HVAC system 14 to deliver heated or cooled air,
or to switch from one to the other. In some embodiments, controller
10 may instruct HVAC system 14 to increase or decrease its air
volume output, or to modify its thermal output.
[0075] In some embodiments, the operational profile can include
instructions not directly related to heating and cooling. For
example, some HVAC systems include filtration equipment,
humidification equipment and the like. The operational profile can
include appropriate commands governing the operation of this and
related equipment.
[0076] FIG. 11 is a flow diagram showing another illustrative
method that can be implemented by controller 10. At block 70,
controller 10 selects a zone. In some embodiments, controller 10
may select a zone based on which zone has the greatest thermal
demand, such as the greatest temperature difference between the
actual temperature in each zone and a current temperature set point
for each zone.
[0077] In some embodiments, controller 10 may include (in MEMORY
block 24) instructions regarding prioritizing of zones. For
example, in a hospital, controller 10 may be instructed to give
first priority to critical rooms such as operating rooms, critical
care rooms, and the like. In a residential application, controller
10 may be instructed to give first priority to a living room or
family room, the priorities may automatically change with time. In
some embodiments, for example, the priority assigned to a
particular zone can change based on time of day and room occupancy.
For example, the family room may be prioritized during the day when
children are present, while a bedroom may be prioritized during
sleeping times.
[0078] Once a zone has been selected, control passes to block 72,
at which time controller 10 determines the thermal demand of the
selected zone. Controller 10 can determine the thermal demand of
the selected zone in any suitable manner, such as those discussed
with respect to FIG. 10. At block 74, controller 10 determines the
thermal energy available to the selected zone as discussed
previously. Control passes to block 76, at which controller 10
calculates an operational profile as discussed with respect to FIG.
9. At block 78, controller 10 regulates the flow of thermal energy
(or a heat delivery rate) into the selected zone based on the
operational profile. A heat delivery rate can be positive,
representing the addition of heat, or it can be negative,
representing the addition of cooled air. The discussion with
respect to FIG. 10 illustrates how controller 10 may regulate heat
delivery into the selected zone.
[0079] FIG. 12 is a flow diagram showing another illustrative
method that can be implemented by controller 10. At block 70,
controller 10 selects a zone as discussed above. Control passes to
block 72, where controller 10 determines the thermal demand of the
selected zone as discussed previously. At block 74, controller 10
determines the thermal energy available to the selected zone. This
can be done in any suitable manner such as described with respect
to FIG. 10.
[0080] Control then passes to block 80, where controller 10
determines when to open or close a damper regulating airflow into
the selected zone. In some embodiments, controller 10 determines a
zone damper open and close time. These times may be calculated as a
function of the thermal demand of the selected zone and/or the
airflow and thus heat delivery rate available to the zone, as
discussed previously. In some embodiments, controller 10 may
calculate several such times, if desired.
[0081] At block 82, controller 10 sends a signal through ZONE I/O
block 28 to either open or close the damper in accordance with the
open/close times previously calculated. Control then passes to
block 84, where controller 10 once again determines an amount of
thermal energy available to the selected zone. The thermal energy
that is available may change, because other zones may have been
opened or closed in the meantime, for example, or HVAC system 14
may have modified its fan speed or thermal output. Controller 10
can check the amount of thermal energy available to the selected
zone at any appropriate interval. In some embodiments, controller
10 can check the amount of thermal energy available to the selected
zone at an interval of about every five seconds, but any suitable
time period may be used.
[0082] If the available thermal energy has changed, as queried at
decision block 86, control reverts back to block 80. At block 80,
controller 10 calculates new zone damper open and/or close times
based on the thermal demand of the selected zone and/or the newly
calculated airflow available to the zone. However, if at decision
block 86 the available thermal energy has not changed, control
passes to block 88 at which controller 10 maintains the damper
position in accordance with the previously calculated open/close
times.
[0083] FIG. 13 is a flow diagram showing another illustrative
method that can be implemented by controller 10. At block 70,
controller 10 selects a zone as discussed above. Control passes to
block 72, where controller 10 determines the thermal demand of the
selected zone as discussed previously. At block 74, controller 10
determines the thermal energy or heat delivery rate available to
the selected zone. This can be done in any suitable manner such as
described with respect to FIG. 10.
[0084] Control then passes to block 80, where controller 10
determines when to open or close a damper regulating airflow and
thus regulating thermal energy delivery into the selected zone. In
some embodiments, controller 10 determines zone damper open/close
times. The open/close times may be calculated as a function of at
least one of the thermal demand of the selected zone, the airflow
available to the zone, the thermal content of the airflow available
to the zone, as discussed previously. In some embodiments,
controller 10 may calculate several such open/close times, if
desired.
[0085] At block 82, controller 10 sends a signal through ZONE I/O
block 28 to either open or close the damper in accordance with the
open/close times previously calculated. Control then passes to
block 84, where controller 10 once again determines an amount of
thermal energy available to the selected zone. Controller 10 can
check the amount of thermal energy available to the selected zone
at any appropriate interval. In some embodiments, controller 10 can
check the amount of airflow available to the selected zone at an
interval of about every five seconds.
[0086] Next, controller 10 determines at block 90 if the thermal
demand of the selected zone has changed. Control passes to decision
block 86, which queries whether the amount of thermal energy
available to the selected zone has changed. If the available
thermal energy has changed, control reverts back to block 80. At
block 80, controller 10 calculates new zone damper open and/or
close times based on the thermal demand of the selected zone and/or
the newly calculated thermal energy available to the zone.
[0087] However, if at decision block 86 the available thermal
energy has not changed, control passes to decision block 92, at
which controller 10 queries whether the thermal demand of the
selected zone has changed. If the thermal demand has not changed,
control passes to block 94 at which controller 10 operates the
damper in accordance with the operational profile. However, if the
thermal demand has changed, control reverts to block 70, at which
point controller 10 selects a zone as discussed previously.
[0088] FIG. 14 is a flow diagram showing yet another illustrative
method that can be implemented by controller 10. At block 96,
controller 10 determines the thermal demand of a zone, as discussed
above. Control passes to block 98, where controller 10 ascertains a
status of at least one other zone. In some embodiments, the status
can include the open/close status of at least one other zone. At
block 100, controller 10 determines, for at least one damper, open
and close times based on the thermal demand of the zone and the
status of at least one other zone (as determined at block 84). In
some embodiments, controller 10 may determine or calculate a series
of damper open/close times, if desired.
[0089] FIG. 15 is a flow diagram showing another illustrative
method that can be implemented by controller 10. At block 102,
controller 10 selects a zone using any suitable criteria as
discussed. In some embodiments, a zone may be selected based on its
relative thermal demand or its previously determined priority.
Control passes to block 104, where controller 10 determines the
thermal demand of the selected zone in any suitable manner as
discussed above.
[0090] At block 106, controller 10 ascertains a status of at least
one other zone, such as the current open/close status. At block
108, controller 10 determines a series of damper open/close times
based on the thermal demand of the zone and the status of at least
one other zone (as determined at block 106). Control passes to
block 110, where controller 10 controls the selected zone by
sending command signals through ZONE I/O block 28 to the zone
damper in accordance with the series of damper open/close times
determined at block 108.
[0091] FIG. 16 is a flow diagram showing another illustrative
method that can be implemented by controller 10. At block 102,
controller 10 selects a zone using any suitable criteria as
discussed. In some embodiments, a zone may be selected based on its
relative thermal demand or its previously determined priority.
Control passes to block 104, where controller 10 determines the
thermal demand of the selected zone in any suitable manner as
discussed above. At block 112, controller 10 ascertains a status of
other zones, such as the open/close status of the other zones.
[0092] Control passes to block 114, at which point controller 10
calculates an operational profile for the selected zone based on
the thermal demand of the selected zone (as determined at block
104) and/or the status of the other zones (as determined at block
112). At block 116, controller 10 operates the selected zone in
accordance with the operational profile by sending appropriate
command signals to the selected zone through ZONE I/O block 28.
[0093] At block 118, controller 10 rechecks the status of the other
zones. Controller 10 can recheck the status of the other zones at
any appropriate interval or time. In some embodiments, controller
10 can check the status of the other zones at an interval of about
once every five seconds. At decision block 120, controller 10
determines if the status of the other zones has changed. If the
status of the other zones has changed, control reverts back to
block 114 and controller 10 calculates a new operational profile
based on the thermal demand of the zone and/or the newly changed
status of the other zones.
[0094] Conversely, if the status of the other zones has not
changed, control passes to block 122, at which point controller 10
rechecks the thermal demand of the selected zone. Controller 10 can
recheck the thermal demand of the selected zone at any appropriate
interval. In some embodiments, controller 10 can check the thermal
demand of the selected zone at an interval of about once every five
seconds. If the thermal demand has changed, as queried at decision
block 124, control reverts back to block 112 and controller 10
ascertains the status of the other zones. If the thermal demand has
not changed, control passes to block 126 at which point controller
10 maintains the damper as specified in the operational
profile.
[0095] FIG. 17 is a flow diagram showing an illustrative method
that can be implemented by controller 10. Controller 10 selects a
zone at block 128, using any suitable criteria as discussed
previously. Control passes to block 130, where controller 10
calculates a zone open time. In some embodiments, the zone open
time can be a function of the thermal and airflow capacity of HVAC
system 14 (FIG. 1) and/or a thermal demand of the particular zone.
Control passes to block 132, where controller 10 ascertains the
status of other zones. In some embodiments, the status can include
an open or closed position status.
[0096] At block 134, controller 10 calculates a compensation value.
In some embodiments, the compensation value can be a function of
the total number of zones compared to the number of open (or
closed) zones. For example, if a given system has ten (10) zones,
and only two (2) zones are open, the compensation value can be a
ratio therebetween. For example, the compensation value can be
10/2=5, which can be used as a speed-up factor for damper
operation. In some embodiments, the compensation value may be, for
example, 2/10=0.2, which can be used as a delay factor, if desired.
At block 122, controller 10 may calculate an adjusted zone open
time by dividing the zone open time calculated at block 130 by the
speed-up factor. Alternatively, the zone open time may be
multiplied by the delay factor to obtain the adjusted zone open
time.
[0097] FIG. 18 is a flow diagram showing another illustrative
method that can be implemented by controller 10. At block 128,
controller 10 selects a zone using any appropriate criteria as
discussed above. Control passes to block 138, where controller 10
calculates a zone open time and sets a variable "W" equal to the
zone open time. In some embodiments, the zone open time can be a
function of the thermal capacity of HVAC system 14 (FIG. 1) and/or
a thermal demand of the particular zone.
[0098] Control passes to block 140, where controller 10 queries the
number of zones in the system and the status of each zone. In some
embodiments, the total number of zones in the system can be
programmed into MEMORY block 24 (FIG. 1). At block 142, controller
10 sets a variable "X" equal to the total number of zones in the
system. At block 144, controller 10 sets a variable "Y" equal to
the number of open zones in the system. Control passes to block
146, at which point controller 10 calculates a compensation value,
set as variable "Z", as equal to "X" divided by "Y". At block 148,
controller 10 calculates a revised zone open time, set as variable
"T", as equal to "W" multiplied by "Z". Control passes to block
150, where controller 10 operates the selected zone using the
revised zone open time "T".
[0099] In some cases, the controller 10 may include a counter or
the like to help track the appropriate open time for a damper. For
example, a counter may be initiated when a particular zone damper
is opened, and may be closed when the counter counts to a
predetermined value. In one illustrative embodiment, the controller
10 may set the predetermined value such that the counter counts to
the predetermined value in the time that the particular zone damper
is to remain open. Alternatively, or in addition, the counter may
count by a counter increment value, wherein the counter increment
value is set such that the counter counts to the predetermined
value in the time that the particular zone damper is to remain
open. Alternatively or in addition, the counter may count by a
counter increment value once during each of a series of counter
period, wherein the counter period is set such that the counter
counts to the predetermined value in the time that the particular
zone damper is to remain open. A separate counter may be maintained
for each zone damper in the system. It is contemplated that the
counter may be implemented in hardware or software, or a
combination thereof, as desired.
[0100] The invention should not be considered limited to the
particular examples described above, but rather should be
understood to cover all aspects of the invention as set out in the
attached claims. Various modifications, equivalent processes, as
well as numerous structures to which the invention can be
applicable will be readily apparent to those of skill in the art
upon review of the instant specification.
* * * * *